By Leah Shaffer
Black Americans die younger than their White counterparts, with an estimated 1.63 million "excess" deaths having occurred between 1999 and 2020. These excess deaths are predominantly attributable to chronic conditions like heart disease or cancer.
In a study published in JAMA Network Open, researchers at Washington University in St. Louis found that the elevated mortality risk among Black Americans is largely explained by greater stress exposure across the lifespan as well as inflammation in later life.
The research came from a unique longitudinal study, the St. Louis Personality and Aging Network (SPAN) Study, that has followed older adults for nearly 20 years. WashU graduate student Isaiah Spears "saw the stark difference between the rate in which our Black participants in the sample have been dying relative to the white participants," and wanted dig into the question of what might be contributing to these racial disparities.
Spears led this research with support from his adviser Ryan Bogdan, the William R. Stuckenberg Professor in Human Values and Moral Development who directs the BRAIN lab in the department of psychological and brain sciences in Art & Sciences as well as other WashU coauthors.
Bogdan noted that the SPAN data offered an opportunity to develop a "cumulative stress index" since it includes a longitudinal cohort with ample data from blood draws and surveys over almost 20 years as well as retrospective reports of experiences during childhood. Much of the research on racial disparities has focused on overt experiences of discrimination (like being turned down for a loan), that may not capture the disadvantage associated with structural racism that generates elevated stress exposure that may prematurely weather individuals to negatively impact health.
Spears wanted to take the "lifespan view" of stress exposure to test whether a heightened burden of chronic stress and its associations with inflammation may plausibly drive elevated mortality risk among Black Americans. To do that, they looked at the extent to stress exposure across the lifespan and its association with inflammatory markers C-reactive protein and Interleukin-6 and how that is associated with racial differences in mortality risk.
They found that the elevated stress exposure experienced by Black Americans across their lifespan is associated with heightened inflammation and that these factors explained roughly half of the elevated mortality risk among Black relative to White Americans in their study.
It's thought that stress shortens life via immune dysregulation and inflammation. The concept of allostatic load, or wear and tear of the body, means that chronic stress can dysregulate body systems and homeostasis leading to dysregulated recovery and response as well as premature aging. "If stress becomes chronic, that could be incorporated into one's homeostasis; you may become less able to mount your biological systems to respond to acute stress challenges and your may be less able to return to a bodily state that promotes regeneration and restoration," Bogdan said.
"Over time continued chronic exposure to stress leads to dysregulation and an earlier breakdown of some of the biological systems in the human body," said Spears, adding too much stress leads to early aging and greater disease risk, all the problems seen in Black populations. The greater stress exposure we see in Black Americans likely has origins in societal structures that have cumulatively disadvantaged Black Americans across generations.
While this study suggests that policy efforts to prevent and attenuate explicit and structural discrimination as well as stress exposure, Bogdan notes that this work also suggests that it will be important to research treatments that may be able to help those exposed and that this would benefit all Americans.
"Addressing large-scale societal issues requires concerted efforts enacted over time. That needle can be extremely hard to move," he said.
"Stress exposure will always be there - so we need to devote more efforts to understand the mechanisms through which stress contributes to adverse health outcomes so that factors could be targeted to minimize health risks among those exposed."
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Spears ID, Gorelik AJ, Norton SA, Boudreaux MJ, Wolk MW, Siudzinski J, Paul SE, Cox MA, Rogers C, Oltmanns TF, Hill PL. Bogdan R. Cumulative Lifespan Stress and Inflammation are Associated with Black-White Racial Disparities in Mortality Among Americans. JAMA Network Open. Published Online: January 26, 2026;9;(1):e2554701 DOI:
10.1001/jamanetworkopen.2025.54701
This study was supported by R01 AG061162 (RB, TFO) and R01 AG045231 (TFO). Investigators were also supported by T32 AG000030 (IDS), NSF DGE-213989 (AJG), F31 AA029934 (SEP).
